/*
 $Id$

 Copyright (C) 2006-2007 by David Cotton

 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
 Foundation; either version 2 of the License, or (at your option) any later
 version.

 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
 Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package fr.free.jchecs.swg;

import static fr.free.jchecs.swg.ResourceUtils.getI18NString;

import java.awt.Component;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.Formatter;

import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JPanel;

import fr.free.jchecs.ai.Engine;
import fr.free.jchecs.core.Game;
import fr.free.jchecs.core.move.MoveGenerator;

/**
 * Composant affichant la valeur de l'évaluation de la position courante d'une partie.
 * 
 * @author David Cotton
 */
final class EvalPanel implements PropertyChangeListener
{
  /** Composant graphique externe. */
  private final JComponent _component;

  /** Partie liée au composant. */
  private final Game _game;

  /** Label affichant la valeur de l'évaluation. */
  private final JLabel _eval;

  /**
   * Construit un nouveau composant d'affichage de l'évaluation de la position.
   * 
   * @param pPartie Définition de partie liée au composant.
   */
  EvalPanel(final Game pPartie)
  {
    assert pPartie != null;

    _game = pPartie;

    final JPanel fond = new JPanel();
    fond.setAlignmentX(Component.CENTER_ALIGNMENT);
    _eval = new JLabel("0.00");
    fond.add(_eval);

    _component = fond;

    _game.addPropertyChangeListener("position", this);
  }

  /**
   * Renvoi le composant graphique affichable.
   * 
   * @return Composant graphique.
   */
  JComponent getComponent()
  {
    assert _component != null;
    return _component;
  }

  /**
   * Réagit au changement dans la définition de la partie.
   * 
   * @param pEvt Evènement signalant le changement.
   */
  public void propertyChange(final PropertyChangeEvent pEvt)
  {
    assert pEvt != null;

    final MoveGenerator disposition = _game.getBoard();
    boolean traitReference = disposition.isWhiteActive();
    final boolean traitAdversaire = !traitReference;
    Engine moteur = _game.getPlayer(traitAdversaire).getEngine();
    if (moteur == null)
    {
      moteur = _game.getPlayer(!traitAdversaire).getEngine();
      traitReference = traitAdversaire;
    }
    if (moteur == null)
    {
      _eval.setText("?.??");
    }
    else
    {
      final int note = moteur.getHeuristic().evaluate(disposition, traitReference);
      final StringBuilder sb = new StringBuilder();
      final Formatter formateur = new Formatter(sb);
      final String pointDeVue;
      if (traitReference)
      {
        pointDeVue = getI18NString("panel.eval.white");
      }
      else
      {
        pointDeVue = getI18NString("panel.eval.black");
      }
      formateur.format("%+5.2f / %s", Float.valueOf(note / 100.0F), pointDeVue);
      _eval.setText(sb.toString());
    }
  }
}
